Ploting an image with 'imshow' of opencv in webots

问题

hi I am using opencv in webots and I want to plot an image . This is the controller:

#include <webots/Robot.hpp>
#include "opencv2/core/core.hpp"
#include "opencv2/highgui/highgui.hpp"
#include "opencv2/imgproc/imgproc.hpp"
#include <iostream>

using namespace webots;
using namespace cv;

int main(int argc, char **argv){

  Robot *robot = new Robot();
  int timeStep = (int) robot->getBasicTimeStep();

  while (robot->step(timeStep) != -1) {
      Mat a1 = imread("/home/alireza/Desktop/1.jpg");
      cv::imshow("test",a1);
  };

  delete robot;
  return 0;
}  

and this is the makefile:

OPENCV = `pkg-config opencv --cflags --libs` 
LIBRARIES = $(OPENCV) 
space :=
space +=
WEBOTS_HOME_PATH=$(subst $(space),\ ,$(strip $(subst \,/,$(WEBOTS_HOME))))
RESOURCES_PATH = $(WEBOTS_HOME)/projects/robots/robotis

CXX_SOURCES = $(wildcard *.cpp)
include $(WEBOTS_HOME_PATH)/resources/Makefile.include

I make it successfully but when I want to run it I face a runtime error about Qt :

[co] qt.qpa.plugin: Could not find the Qt platform plugin "xcb" in ""
[co] This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.

I really need help.

来源：https://stackoverflow.com/questions/54556519/ploting-an-image-with-imshow-of-opencv-in-webots